Nicotine replacement therapy is the administration of nicotine by other means than smoking. This change in the way nicotine is delivered prevents the harmful effects of smoking and is usually used in smoking cessation.
Types
Nicotine replacement therapy can be administered in several forms. The type used depends on the patient and what fits into their lifestyle best. The forms available include:
Nicotine patches – transdermal (through the skin)
Nicotine gum – orally (through the...

A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.